Exhaust nozzle



Mal'l'l 31, 1931. B. T W|| L|STON 1,798,771

EXHAUST NOZZLE Filed Jan. 19, 1929 2 Sheets-Sheet l F'y I..

EXHAUST NOZZLE Filed Jan. 19. 1929 2 Sheets-Sheet 2 Patented Mar. 31, 1931 UNITED STATES PATENT oFFlcE BELVIN T. WILLISTON, F SOMERVILLE, MASSACHUSETTS, ASSIGNOR TO CONSOLIDATED ASHCROFT HANCOCK COMEANY, OF NEW YORK, N. Y., A CORPORATION OF DELA- WARE EXHAUST NOZZLE `Application led `January 19, 1929. Serial No. 333,621.

This invention pertains to draft regulators for furnaces, and more particularly to exhaust nozzles, and while of more general utility, the invention is herein disclosed as applied to a locomotive wherein such nozzles are commonly employed. When thus used, the exhaust nozzle is usually arranged directly below, but spaced from, the lower end of the smoke stack, and is adapted to deliver l0 exhaust steam upwardly into the stack, thus entraining with it the smoke and furnace gases and ejecting them through `the stack, at the same time creating a draft through the furnace. For best and most economical operations of a locomotive, an exhaust pressure of about four `pounds isusually maintained, and the 'present invention provides for the efficient use of exhaust steam at this relatively low pressure to secure a powerful draft. With this object in view, instead of delivering the steam as a single solid jet `through a plain nozzle, I so divide the jet as y to provide a greatly'increased area of contact between the` flowing steam and the surrounding furnace gases, and lead a portion of the `furnace gas inwardly toward the center of' the nozzle through appropriately shaped channels, thereby greatly increasing the ejector action of the steam.

While I am aware that attempts have been made to increase the ejector'action by providing obstructions in the nozzle orifice so as to break up the continuity of the flowing steam jet, such arrangements are more or less uncertain in action and do not substantially increase the exposed surface of the steam j et for frictional engagement with the furnace gas.

In the accompanying drawings I have illustrated one embodiment of the present invention by way of example, and in the drawings:

Fig. 1 is a fragmentary diagrammatic vertical section ofthe forward portion of a locoin its relation to the stack p Fig. 2 is a plan view to larger scale of my improved exhaust nozzle;

Fig. 3 is a vertical section substantially on the line 3-3 of Fig. 2; l

motive showing my improved exhaust nozzleV the usual internal deflector plates and screens defining the chamber 2 into which the lower end of the stack 3 opens. Usually, as illustrated, the lower end of the stack is flared outwardly and downwardly so as 'to increase the ejector action of the steam jet.

`The usual exhaust pipe 5 extends upwardly into the lower part of chamber 2, substantiallyin axial alignment with the stack 3, and is shown as provided with the usual radial flange 6 forming a seat for the reception of the exhaust nozzle 7 .y

Referring more particularly to Figs. `2, 3 and 5, my limproved nozzle comprises an annular body portion 8 adapted to lit snugly onto the'uppe'r end of the exhaust pipe `5, and preferably having a radial flange 9 provided with suitable openings to receive bolts for attaching it to the flange 6 of the pipe 5. The exhaust nozzle has a Steam admission opening 10 registering with the bore of the exhaust pipe 5, and above the flange 9 the nozzle comprises a substantially cylindrical portion or shell 11. i This shell is provided with a plurality of circumferentially spaced openings 12, here shown as vertically elongate slots disposed substantially ninety degrees apart and below the upper edge of the shell.

A plurality of conduits 13 lead inwardly from the shell 11 toward the center of the nozzle. These conduits are preferably in the form of upwardly open substantial U-shaped webs whose side walls and bottoms are preferablyy integral with the shell 11. These channel-like webs preferably merge at the center ofthe nozzle, as indicated at 16, and thebottoms 15 of the web members slope up wardly from the lower ends of the slots 12 toward the center of the nozzle so that the guide channels 14 are deepest adjacent to the shell 11 and gradually decrease in depth toward the vcenter so as to supply substantially equal quantities of gases to portions of steam jets served by these passages and also to provide for compactly arranging jets of maximum capacity for eiicient operation. Each channel 14 registers with one of theV openings 12, and the U-shaped web-like conduits 13 divide the space within the shell 11 so as to f -orm a plurality ofYindependent` segmental steam-delivery' passages 17. Adjacent pasL sages are spaced apart a distance equal to the width of the intervening conduit 13 so that the emerging jets of steam are entirely independent where they leave the nozzle, each jet presenting a peripheral surface comprising an arcuate outer surface, and substantially straight intersecting inner surfaces: The channels 14 provide free access for" the furnace gases to enter radially between'the steam jets so as to Contact with the inner surfaces of the several jets, and by the division of the steam into a. plurality ofv separated jets, as above described, a much larger surface than usual is provided for frictional engagement of the steam' with the gases this greatly increases the ejector effect so that with a given quantityv of steam at a given pressure it is possible to obtain a much more powerful draft than' when employing a plainvnozzle delivering all of the steam inthe forn of a snglejet. i

In Fig. 4' I have shown any improved nozzle.

applied to a` stack of somewhat cli-Herent form. In'this figure the shell of the smoke box is indicated at 1a, the stack at 3a, and the -ch'amber, into which the stack opens, Lat 2a.

In this case the stack proper is relatively short, but is provided with a series of annular truncated, conical skirt members y18 'coaxial withthe stack proper and spaced apart vertically and adapted to increase the ejectork effect. The' exhaust pipeV 5'a is provided with my improved nozzle 7, and when this combination is employed an'even more powerful draft is obtained than in the arrangement i of Huid, resulting from the use of this nozzle,-

shoWn inFig. 1,- s'ince the increased volume when delivered into the lowermost skirt 18 produces an unusually high velocity which in turn reacts to entrain more gas, thus progressively adding to the ejector eect;

Vliile I have shown the gas conduits 13 of the nozzle as consisting of integral :channellike Webs, I contemplate that these conduits may be formed as independent elements secured in any desired manner within the body of the nozzle proper, and while I have shown these conduits as of channel form, open towards the delivery yend ofthe nozzle,- I contemplate that other forms of conduit may be employed, provided theyfurnish a substantial passage for the delivery ofthe furnace gases into the spaces between the several jets. Moreovenwhile I have here shown the nozzle as provided with means defining four independent steam jets, I do not Wish to limit the invention to the precise number of jets employed, nor in the broader aspects of the invention to the complete separation of the several jets,4v since desirable results may be obtained with af` greater or lesser number of jets, and with somewhat less than the maximumpossible inner ,surfaces of the jets/exposed tothe gas. Moreover the proportions of the parts of the" nozzle'slmaybe-v'a'ried as circumstances may Warrant, and I regard all suchchanges as above suggested as falling within the spirit of the invention.

I claim:

1-. Asnv exhaust nozzle comprising an: annular body portion and means providing passages for conducting gases from the vrim ofthe body to itsaxis, said conducting means defining a plural-ity ofspaced: upwardly di` rected steam jets so that the steam delivered by the nozzle exposes a surface substantially greater than that ofa solid cylindrical jet forentra'inment of the gases delivered said conducting mea-ns, said gas passages be# ing convergent inwardly Atoward the center of the nozzle for supplying gases-to vissuing steam approximately in proportion to the onissuing steam:

ular body portion and a" plural-,ity lo'i channel members extending.,inwardlyy from the .r'im of the body to its center,- said channel members defining a; plurality of.l steam de# livering passages adapted tQ- deliver spaced independent 'steam jets, the channel members providing passages 4for. c 'ond-ucting gases `rinwardly from outside of the'body portion and rdelivering said gases in the spaces between the steam jets, the gas passages conyerging inwardly toward thev center approxi-mately in proportion to the entraining arealof the respective jets, whereby substantially equal quantities of gases may be supplied to all portions of all of the jets.-

8. An exhaust nozzle comprising a 'body portion having an attaching flan-ge and a cylindrical Wall provided with circumferentially spaced openings, and gas conductors'n of channeleectio leading inwardly from the respective openings and merging at the center, said channel sections being open toward the discharge end of the nozzle and defining a plurality of segmental steam delivi ery passages spacedapar't by the interposed conductors, the sectional ow area of the gas conductors decreasing toward the center so that substantially equal quantities of gases may be supplied to all sides of the jets and jets of maximum capacity may be compaetly arranged for ei'cie'nt operation.v

4. An exhaust nozzle ofthe class described, comprising an attaching flange and a cylindrical wall extending upwardly therefrom,"

cireumferentially spaced openings disposed between the flange and the upper edge of the cylindrical Wall, radially disposed channel members registering at their outer ends with said openings and communicating with each other at the center of the nozzle, the outer side walls of the channel members cooperating with the cylindrical wall to define jets for exhaust steam, the channel members being open at the top throughout their length for supplying gases to adjacent jets, the bottoms of the channel members being inclined up Wardly toward the center of the nozzle to provide passages diminishing in sectional flow area toward the center of the nozzle for supplying substantially equal quantities of gases to the portions of the jets served by said passages.

5. The combination as set forth in claim 4, wherein the channel members are of like dimensions and are symmetrically disposed to define jets of like size.

Signed by me at Boston, Massachusetts, this 18th day of January, 1929.

BELVIN T. WILLISTON. 

